<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
	<div id="app"></div>


	<script type="text/javascript">

		// [[scope]] --> 作用域链
		
		/*function a(){
			function b(){
				var b = 123;
			}
			var a = 123;
			b();
		}
		var glob = 100;
		a();*/


		// 执行函数
		/*function a(){
			function b(){
				var bbb = 234;
				console.log(aaa); 
			}
			var aaa= 123;
			return b;
		}
		var demo = a();
		demo();*/





	</script>

</body>
</html>